Electric weft detector for looms



Patented June 24, 1947 ELECTRIC WEFT DETECTOR FOR LOOMS Charles B.Keenan, Worcester, Mass., assignor to Crompton & Knowles Loom Works,Worcester, Mass., a corporation of Massachusetts Application March 18,1946, Serial No. 655,103

9 Claims.

This invention relates to improvements in electric weft detectors forlooms and it is the general object of the invention to provide adetector in which the bobbin engaging detector finger is mounted forsliding movement in a support or base and is permanently connected tothe spring which holds it normally in rearward detecting position.

Weft detectors employing sliding detector fingers are customarilyequipped with small compression springs surrounding the fingers to holdthe latter in detecting position. These springs occasionally become partof the current conducting circuit and are injured by heating. It is animportant object of my present invention to use a sheet metal springhaving ample cross section for conducting the electric current neededfor the detecting circuit, and attach the spring to the detector fingerpermanently so that the connection between the spring and the fingerwill ofler a minimum of resistance to the flow of electric current.

The base which supports the detector finger is ordinarily provided withbinding posts or the like for connection with wires of the external loomcontrolling detecting circuit. In order that there may be a minimum ofresistance between these binding posts and the spring it is a furtherobject of my present invention to fasten the spring permanently to itsbinding post to provide a continuous metallic circuit from the tip ofthe detector finger through the spring to the binding post.

In order that the spring and its attached detector finger and bindingpost may be readily assembled on the detector it is another object of myinvention to provide a base having a large enough opening to permitplacement of the binding post through a part of the base. Another partof the base is provided with a removable bearing element such as a capbearing for the detector finger. In a modified form of the invention thedetector finger passes through the sheet metal spring so that it mayhave a bearing surface at two points on the base which are behind thebinding post.

With these and other objects in view which will appear as thedescription proceeds, my invention resides in the combination andarrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein two forms of the invention are setforth,

Fig. l is a plan view of the preferred form of my improved weftdetector,

Fig. 2 is a side elevation looking in the direction of arrow 2, Fig. l,

Fig. 3 is a vertical section on line 33 of Fig. 1,

Fig. 4 is a transverse vertical section on line 4-4 of Fig. 1,

Fig. 5 shows the detector and binding post and the spring connectedthereto with the spring in its normal form prior to application to thedetector,

Fig. 6 is a plan view of a detector made according to the modified formof my invention,

Fig, 7 is a longitudinal vertical section on line l| of Fig. 6,

Fig. 8 is a vertical section on line 8-4 of Fig. 6, and

Fig. 9 is a view similar to Fig. 5 but showing the modified form ofdetector finger used with the modified form of the invention.

Referring particularly to Figs. 1 and 5 which show the preferred form ofthe invention, Ill indicates a support mounted on the loom and havingthe detector D secured thereto by bolts II. The detector includes a baseI! made of insulating material having side members [3 and H, a rearbearing l5, and a front cross bar l6. These parts inclose asubstantially rectangular elongated opening l'l extending between thebolts H. The base may be cut from fiat material or may be molded. Thebearing I5 is drilled to provid two parallel slide bearing bores 20 and2| extending in the direction of the length of slot or opening H.

The base I2 is provided with two detector elements designated generallyat 25 and 26, and since these detectors are alike only one of them willbe described in detail. The detector element 25 includes an electricdetector finger 21 made preferably of metal and slidable in bearing bore20 and having a tip 28 driven thereon for engagement with the ferrule Fof a bobbin B when the latter is depleted of weft during a detectingoperation of the loom. The detector finger, which is shorter than thelength of slot 11, extends forwardly through the bearing l5 and hasbrazed, soldered, welded, or otherwise permanently attached to theforward end thereof the rear end 29 of a sheet metal spring 30. Theforward end 3| of the spring is permanently connected to a metallicbinding post or electrode 32 preferably attached to the spring in thesame manner that the rear end 29 is attached to the detector finger. Thebinding post is sufilciently long to extend forwardly from the crosswall or bar ii to have attachment with a wire forming part of thedetecting circuit. The latter is not indicated in the drawings but willinclude wires 33 and 34 attached to the detector elements 25 and 26,respectively.

After the two detecting elements have been made as shown in Fig. 5, thedetector fingers 21 will be placed in slot l1 and slid rearwardlythrough their respective bores 20 and 2|, after which the tips 28 willbe driven onto the rear ends of the fingers 21. The forward ends of thesprings are then bent so that their binding posts can be slipp d throughholes 35 formed in the cross wall or bar l6, after which the circuitwires can be attached. The spring 30 operates normally to hold thedetector in rearward position for engagement with the bobbin B, and whena ferrule engages both the tips 28 the wires 33 and 34 will beelectrically connected to each other, the circuit through the detectorelements being unbroken and continuously metallic. The opening I1 issufiiciently long to permit a considerable forward movement of thedetector fingers, and is also long enough to permit insertion of thebinding posts through the cross bar IS. The bearing I5 is of sufiicientwidth to afford adequate support for the fingers 21.

In the modified form of the invention shown. in Figs. 6 to 9 thedetector D' has a base 40 somewhat similar to base I2 and having a rearbearing 4| corresponding to bearing I5 and provided with a cap 42. Thefront part of the base 40 is provided with a cross bar 43 correspondingto cross bar |6. The base 40 is made of insulating material and isprovided with front and back openings 45 and 46, respectively, which areseparated by a transverse bearing 41 in which are located two horizontalparallel spaced bores 48 which serve as slide bearings.

The detector element for the modified form of the invention is shown inFig. 9 and includes a sheet metal spring 50 which in its normal form isfiat. Secured to the forward end of spring 50 is a binding post 5|corresponding to the binding post 32, while the rear end of the springis permanently connected to a detector finger 52 having a bobbinengaging tip 53. The finger 52 extends on both sides of the spring andis permanently connected to the latter, as is also binding post 5| inthe same manner as that described for the preferred form of theinvention.

In assembling the modified form of the invention the cap bearing 42 willbe removed and the forward ends 55 of the detectors will be insertedinto the rear ends of the bores or slide bearings 48 with the rear endof spring 50 in opening 45. The detector fingers 52 are resilient andcan be bent sufiiciently to permit this assembly with respect to thecross bearing 41. The binding posts 5| are then placed in opening 45 andinserted through the front cross bar 43 as already described for thepreferred form of the invention. The binding posts of both detectorelements 52 may then be connected to wires 56 and 51 forming part of thedetecting circuit. In this modified form of the invention it will beunderstood that the detector fingers are supported by two spaced slidebearings between which is located the rear end of springs 50.

From the foregoing it will be seen that I have provided an electric weftdetector including a detector element made up essentially of three partsthe first of which is the bobbin engaging detecting finger, the secondof which is the sheet metal spring, and the third of which is thebinding post. These three parts are permanently connected to each otheras by the methods already described so that a continuous uninterruptedelectric circuit can be established between the detector finger tip andthe binding post. In the preferred form of the invention the bearing I5is made sufflciently wide to afford ample support 4 for the detectorfingers 21, but in the modified form of the invention the bearing 4| maybe narrower than bearing |5 due to the forward bearing 41. Also, in themodified form of the invention, the detector finger 52 extends onopposite sides of the spring 50 and the openings 45 and 43 are ofsumcient length to permit insertion of the binding posts 5| through thefront cross bar 43 and accommodate normal forward movement of thedetector fingers during engagement of the tips 53 with a full bobbin.The forward ends 55 of the detector fingers 52 may project through thebores 48 during certain at least of the de tecting operations, but willnot strike the binding posts 5|. In the preferred form of the inventionslot H is longer than either the detector fingers 21 or binding posts orelectrodes 32 thereby permitting entry of these parts into theirrespective bearing bores and holes 35 from within the slot.

Having thus described my invention it will be seen that changes andmodifications may be made therein by those skilled in the art withoutdeparting from the spirit and scope of the invention and I do not wishto be limited to the details herein disclosed, but what I claim is:

1. A detector element for an electric weft detector, said elementcomprising a normally fiat elongated sheet metal spring, a metallicdetector finger permanently connected to one end of the spring andextending laterally therefrom, and a binding post permanently connectedto the other end of the spring and projecting laterally therefrom.

2. A detector element for an electric weft detector, said elementcomprising a normally fiat elongated sheet metal spring, a metallicdetector finger permanently connected to one end of the spring andextending laterally therefrom on opposite sides of the spring, and abinding post permanently connected to the other end of the spring andprojecting laterally therefrom.

3. A detector element for an electric weft detector, said elementcomprising a normally fiat elongated sheet metal spring, a metallicdetector finger permanently connected to one end of the spring, and abinding post permanently connected to the other end of the spring, saidfinger and bindin post both extending laterally of said spring on thesame side thereof.

4. In an electric weft detector for looms, said detector having twospaced electric detector fingers, a base made of electric insulatingmaterial having an opening therein, a front wall on the base forward ofsaid opening, rear slide bearings on the base behind said opening, thedetector fingers being slidable in the bearings, a binding post for eachfinger extending through and secured to said front wall, and a sheetmetal spring for each finger, each spring having a rear end permanentlyconnected to the corresponding finger and normally in front of theassociated bearing and having a front end permanently connected to thecorresponding binding post behind said front wall, said springs normallyvvul u having a front end against said front wall and in said openingand having a rear end in front of the corresponding bearing and in saidopening, and a binding post for each spring extending through said frontwall and secured therein. each post being permanently connected to thefront end of the corresponding spring, each detector finger slidablymounted in the bearing corresponding thereto and having the forward endthereof permanently connected to the rear end of the associated spring,said fingers being movable forwardly into said opening against theaction of said springs and toward said binding posts.

6. In an electric weft detector for looms, a base made of electricinsulating material, a front wall forming part of said base, a pair ofrear slide bearings formed on the rear of the base, an intermediatebearing between said rear front wall and said bearings and formed withsaid base, a pair of detector fingers each slidable in a rear bearingand said intermediate bearing, a pair of binding posts secured in saidfront wall, one for each finger, and a pair of sheet metal elongatedsprings, each spring having the front end thereof permanently connectedto a binding post and having the rear end thereof permanently secured toa finger between said intermediate and rear bearings, said springsnormally pressing against said rear bearings and normally maintainingthe fingers in rear position, said fingers being slidable forwardly insaid bearings each toward the corresponding binding post against theaction of the associated spring.

7. In an electric weft detector for looms, said detector having twoelectric detector elements, a base made of insulating material andhaving an elongated horizontally extending slot therein, a bearing onsaid base behind one end of said slot, each electric detector elementcomprising an elongated sheet metal spring to one end of which anelectric detector finger is permanently connected, and means securingthe other end of each spring to said base, said detector fingers beingslidably mounted in said bearing and being of less length than thelength of said slot to facilitate rearward sliding of said detectorfingers from a position in said slot into said bearing.

8. In an electric weft detector for looms, said detector having twoelectric detector elements, a base made of insulating material andhaving an elongated horizontally extending slot therein, a front wall onsaid base in front of one end of said slot, and a slide bearing on saidbase behind the other end of said slot, each electric detector elementcomprising an elongated sheet metal spring to one end of which ametallic detector member is permanently connected and to the other endof which an electrode member is permanently connected, said detectormembers being slidable in said bearing and said electrode membersextending through said wall and the ends of said springs being betweensaid wall and bearing, said slot being longer than either of saidmembers to enable the detector member to be inserted into said bearingand said electrode member through said wall from within said slot.

9. In an electric weft detector for looms, said detector having twospaced electric detector fingers, a base made of electric insulatingmaterial, a front wall forming part of said base, spaced front and backbearings formed on the base behind the front wall, said detector fingersslidably mounted in said bearings, a. pair of sheet metal elongatedsprings, one for each member, each spring having a rear end permanentlyconnected to the corresponding finger between said bearings, and a pairof binding posts secured to said front wall, each post permanentlyconnected to the front end of one of said springs.

CHARLES B. KEENAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PA'I'EN'IS Number Name Date 2,392,913 Geier Jan. 15, 1946FOREIGN PATENTS Number Country Date 525,997 Germany June 1, 1931 IIUUI H

